docs: def coords(self):
          """
          A tuple of two `~numpy.ndarray` containing the ``y`` and ``x``
          pixel coordinates of unmasked pixels within the source segment.
  
          Non-finite pixel values (e.g. NaN, infs) are excluded
          (automatically masked).
  
          If all pixels are masked, ``coords`` will be a tuple of
          two empty arrays.
          """
  
          yy, xx = np.nonzero(self.data_cutout_ma)
          return (yy + self._slice[0].start, xx + self._slice[1].start)